It is known to use one or more flexible conduits to collect and flow hydrocarbon products from an underwater wellhead to a surface support. Such conduits can be completely or partially tensioned, or not tensioned. The surface support can be a floating buoy, a ship, or a platform which is floating or fixed to the bottom of the body of water.
When it is necessary to carry out working of the submarine well, one connects between a surface support which can be the same as the surface support to which the flow conduits are connected, a vertical line through which the tools used to work the well can descend or can be lowered by gravity.
This makes the working procedures time consuming and complicated, and requires, in addition, at least one supplemental conduit or flow line.